1. History of the Technology
Two of the many practical problems confronting installers of large athletic flooring constructions are dampening vibration and avoiding damage to the floor resulting from the ineluctable deterioration caused by moisture. Since the installation cost of such floors is expensive, there has been a longfelt need to solve such problems. Most sports floors are poor vibration and shock absorbers; they become unstable when exposed to water because the wood members of the subfloor components expand and contract and tend to warp and ultimately become loosened and this causes the whole floor construction to develop dead spots and become unstable and vibrate and the exterior floor surface no longer provides a reliable playing surface having the desired consistent uniform ball-bounce response. The prior art has long been in search of a flooring construction that is assembled quickly, that reduces vibration, absorbs shock, is moisture resistant and provides a faster, stable playing surface without vibrations and dead spots on which a round ball has a livelier more consistent bounce.
2. Discussion of the Prior Art
A shock absorbent athletic flooring system without vibrations has been the elusive object of many patent inventions. Unfortunately, a lot of athletic floors are too loose and have floating members and dead spots, or they are fastened so tight that there is little or no shock absorbing capacity. The prior art floors are difficult to install and all suffer from having guide channels which support the subfloor nailing beds which channels are rendered immobile because they are fastened directly to a concrete foundation; see the Counihan, Grenau and Amholt patents. Regardless of the insertion of a myriad of springs, foam pads, and such like into the subfloor, the channel guideways in the prior art are pinned down directly to the foundation so the floor can not breathe and rise above the foundation. Representative prior art disclosures include the following U.S. Patents: Allen U.S. Pat. No. 2,317,015; Anderson U.S. Pat. No. 2,317,428; Strom U.S. Pat. No. 2,368,620; Shumaker U.S. Pat. No. 2,539,038; Omholt U.S. Pat. No. 3,271,916; Omholt U.S. Pat. No. 3,577,694; Morgan U.S. Pat. No. 3,713,264; Counihan U.S. Pat. No. 4,599,842; Grenau U.S. Pat. No. 4,856,250; Counihan U.S. Pat. No. 5,016,413; Shelton U.S. Pat. No. 5,526,621; and Counihan U.S. Pat. No. 5,647,183. The prior art floors are expensive to install because of the expense of labor and materials.
This invention concerns a flooring construction which can move up and down within defined deflexure limits. The floor has a novel subfloor assembly which is elevated above its foundation base. The subfloor sections are separated by a gap from each other; they do not touch each other. This reduces vibration in the total floor construction. This invention is a resilient subflooring construction for assembly of a top floor on a foundation which comprises a plurality of spaced apart parallel layers of underlayment members extending longitudinally along the foundation, each having an outside edge and an inside edge. The underlayment members are illustrated by reference signs 12 and 13 in FIGS. 2 and 4. A plurality of spaced apart parallel channel means support the underlayment members and they also extend longitudinally along the foundation, each channel has a closed horizontal top and bottom side in parallel with the plane of said foundation, and they have two vertical sides comprising an opening into the channel at one side and a closed vertical side between said horizontal top and bottom sides and each vertical side is perpendicular to the plane of the foundation. The inside edge of the underlayment member is in engagement with the channel extending through its opening at one end to be supported inside the channel. The channels are elevated above the foundation surface by a plurality of anchoring clip means for engaging the channel to the foundation. Each clip is comprised of three members including a horizontal tab engagement member at its top for engagement inside the channel, a vertical riser member at its middle to permit downward and upper movement of the construction, and a horizontal tab fastening member at its bottom, facing in an opposite direction from the top tab member, for fastening to the foundation. The anchoring clip is illustrated by reference sign 6 in FIGS. 2 and 4. The closed vertical side of the channel has a vertical deflexure slot aperture for engagement with the horizontal tab member of the anchoring clip with each vertical deflexure slot positioned for such engagement which permits deflexure movement of the construction downwards and limits the extent of its upward movement by the height of the vertical riser member of the anchoring clip. The top floor surface is fastened by fastening means such as nails to underlayment members, and the horizontal fastening tab at the bottom of said anchoring clip is fastened by fastening means, such as a pin, to said foundation. The subfloor section comprises c-channel support means having deflexure slots or apertures, layers of wood underlayment which serve as a nailing bed, and deflexure anchor clips that slidably engage the channels and foundation with each other, but they only interlock indirectly with the foundation base. The product of this invention is a superior flooring construction which was not possible to assemble using the prior art components and methods of fabrication. The underlayment is a nailing bed consisting of two layers of wood panels, arranged in parallel to the upper hardwood strips surface which underlayment is adapted for engagement in an open face of c-channel support means which have deflexure slot cut-outs to form apertures which are engaged by the anchor clips. The anchor clip comprises three members including a top member which is a tab that is inserted into deflexure slots in the channel which are apertures cut in the bottom faces of the c-channels which are in registered alignment. The open face of the c-channel envelops the inside edge of the bottom layer of the wood underlayment as illustrated in the drawings described in detail herein. This bottom layer of underlayment is superposed on strips of parallel resilient pad materials centered at about eight to twelve inch intervals on the surface of the foundation which causes the underlayment and c-channel support means of the construction to be elevated above the foundation so that the subfloor has no direct contact with the foundation surface and is slidably and indirectly anchored thereto by means of the bottom tab member of the anchor clip fastening means which permits the entire floor construction to move slidably up and down along the juncture of the aperture cut in the channel and the vertical riser deflexure member 10 which is the middle vertical member of the anchor clip 6 as illustrated in the drawings; this capacity for such reciprocal motion enables the floor to respond to external forces acting upon the hardwood floor board surface of the flooring construction. In this novel construction all of the open faces of the c-channels support means are aligned with their open faces pointed in the same horizontal direction which is in the direction back to the starter-wall of the construction. No c-channel has an open face pointing in an opposite direction to another c-channel. As illustrated in FIG. 4 of the drawings, the wood underlayment is supported in the open face of the c-channel. This floor construction is tighter than the prior art floors so it provides more resistance to a bounced ball and the result is a livelier floor, yet, at the same time its capacity for deflexure movement absorbs shock and vibration.
The best analogy for an understanding of the vibrating dampening effect which is a characteristic of this inventive floor is the example of throwing a pebble into a pond and creating contiguous concentric circles which evolve from the center of the pond to the outside edge of the pond. Since the subfloor sectional component of the floor of this invention are separated from each other, and are not contiguous, vibrations are not transmitted throughout the flooring construction.
As discussed in detail hereinbelow, when a second subfloor assembly is positioned next to a first subfloor assembly about a one-quarter inch gap is left between the edges of the plywood underlayments where the component subfloor sections do not butt up against each other on the foundation. The purpose of setting this one quarter inch gap between adjacent subfloor assembly sections is to dampen vibrations and permit the expansion and contraction of the wood to take place without the consequence of butting wood against wood and causing squeaking, or rubbing of wood against a steel C-Channel and causing squeaking. Without leaving the intentional gap between subfloor sections, the floor would experience stress over a period of time and could go crooked and buckle-up if the sections butted up against each other. The top layer of plywood is cut in a groove cut-out longitudinally along the length of the C-Channel so that the top surface of the C Channel is exposed. The reason that this groove is cut is to avoid unevenness of the subfloor if the top layer of the plywood were placed directly onto the top surface of the C-Channel.
Also keeping the C-Channels elevated above the concrete foundation base overcomes the problem of water condensing over the substantial square foot area of the concrete base which would inherently contain uneven surfaces and low spots of water wells or pools; this invention eliminates this problem by elevating the entire subfloor assembly above the concrete foundation base and leaving gaps between sections of subflooring.
The above described subflooring constructions may be preassembled in sections, e.g. eight feet by fifteen inches, at a factory site, and attached on site of the floor to the base foundation. The preferred floor comprises gaps of about one quarter inch between each preassembled subsection which gaps can be covered-over by nailing the top hardwood floor boards, e.g. maple wood, to the underlayment wood nailing bed in side-by-side relationship superposed and transversely spanning the c-channels which may be centered, e.g. at fifteen inch intervals. The layers of wood underlayment may be nailed or glued to each other; the preferred underlayment is three ply or four ply plywood. This novel elevated channel-underlayment-anchor-deflexure clip system exhibits more holding power in the presence of moisture and reduces vibration. An especially useful feature of the floor product of this invention is the speed and ease of assembly and installation of the subfloor sections.
Another feature of this invention is that it reduces the number of c-channel support means which form the subfloor sections. This reduction in the number of construction parts inherently reduces the amount of labor and time and material required to assemble the flooring construction. The anchor deflexure clip fastening means are spaced apart at about twenty four (24xe2x80x3) inch intervals along the deflexure slot side of the c-channel. The hardwood maple outer floorboards are nailed directly into the plywood underlayment over top of the gaps between subfloor sections, and this tight-joined connection compensates for securing only one inside edge of the plywood underlayment inside the open face of the c-channel instead of engaging both the outside and inside edges of the plywood panel to the c-channel. The deflexure slots or apertures in the c-channel and the anchor clip deflexure fasteners of this invention may be cut as illustrated in FIG. 4, numeral 7 herein which shows an aperture in the form of a T-slot, and they may be constructed from the materials and methods illustrated and explained in detail in my earlier Chambers U.S. Pat. No. 6,073,409, e.g. FIGS. 4-7 for more details.
The underlayment means of this invention is a nailing bed which comprises a subfloor component of two layers of plywood having a top layer and a bottom layer which latter is firmly secured in horizontal fixed retaining engagement within the open face of a plurality of elongated spaced parallel c-channel support and guide means having deflexure slots or apertures which are slidably engaged by the vertical riser elements of a plurality of deflexure tab fastening means (described in my U.S. Pat. No. 6,073,409) which indirectly and slidably anchor the c-channel means to the surface of a base foundation, such as concrete, yet permit the channel means and plywood layers to slide up and down the distance of the height of the vertical riser member of the deflexure tab fastening means. The surface of the c-channel which faces the bottom of this inventive flooring construction, and the bottom surface of the lower layer of plywood are both elevated over the base foundation substance, such as concrete; the reason why they are elevated is because the plywood components are superposed on top of a plurality of elongated spaced apart strips of flexible resilient material, such as rubber pads or foamed closed cell polyethylene or polyurethane foam material, and the resilient strips are placed directly on top of the surface of the foundation base. If desired a film of polyethylene moisture barrier material may be interposed between the strips of flexible resilient material and the foundation base surface to reduce the damaging effects of moisture and water vapor on the wood members of the construction. The foregoing construction provides a stable athletic floor that is reproducible and relatively free of vibration. The floor is capable of rising and lowering, but the distance traveled is governed and restricted by the height dimensions of the resilient pads placed under the bottom surface of the wood underlayment, the deflexure slots cut in the c-channel, and the vertical middle deflexure riser member 10 of the anchor clips. The floor construction slides up and down along the boundaries of the vertical riser member of the anchoring deflexure clip which is engaged in the deflexure slot aperture cut in the perpendicular panel of the c-channel.